Pet exercise ball



FIG. 1 is a right, front and top perspective view of a pet exercise ball according to the present invention;

FIG. 2 is a top view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a right side view thereof; and,

FIG. 7 is a left side view thereof.

The portions of the drawings shown in broken lines represent environmental structure and form no part of the claimed design. 

The ornamental design for a pet exercise ball, as shown and described. 